Download Earth_s_Atmosphere_Notes_2010

O’Wednesday
O’March 17, 2010
• Open your science notebook and
write today’s date and set up your
Cornell notes.
• Finish Atmosphere notes.
• Books open to page 513.
• Goal: What is the composition of the
atmosphere?
Candle Burn
• Compare and contrast what
happens in each of the beakers
Guiding Questions
• What is weather?
• What is the composition of the
atmosphere?
• What is air pressure?
• How does air temperature and air
pressure change with altitude?
What is weather?
• How many words can you think that
describe what the weather is?
What is Weather?
Weather is the current condition of the
atmosphere at a specific time and place.
A Meteorologist is a person who studies the
weather.
What are the ingredients for weather?
– Atmosphere
– Sun (energy)
– Water
What is Earth’s Atmosphere?
P. 512
The atmosphere (aka the air) is an envelope or
layer (a sphere) of gases, solids and liquids that
surrounds the earth.
QuickTim e™ and a
TIFF (Uncompressed) decom pressor
are needed to see this picture.
What is air made up of?
Composition of Earth’s Atmosphere
Nitrogen (N2) ~ 78%
Oxygen (O2) ~ 21%
Argon (Ar) ~0.93%
All Others
Carbon Dioxide (CO2) ~0.03%
Water Vapor (H2O)g ~0 to 4%
Trace (very small amounts) Gases
– Neon, Helium, Methane, Krypton,
Xenon, Hydrogen, Ozone.
Nitrogen
Most abundant element in atmosphere (78%).
Always occurs as N2.
It is a gas at surface temperatures.
Un-reactive, somewhat inert, which means it does not
easily combine with other elements.
Vital to life (Nitrogen Cycle).
Most of your breath is Nitrogen.
Oxygen
2nd most abundant element in atmosphere
(21%).
Found in nature as O2
Very reactive, supports combustion (burning)
Extremely vital to most living things
Argon
3rd most abundant element in atmosphere
(0.93%).
Completely inert, does not combine with other
elements.
Used in neon lights
Water Vapor
Water Vapor is water in the form of a gas.
– Remember the states of matter?
It is invisible, not the same thing as steam.
– Steam is water vapor (the gas) condensing back
into liquid water.
The amount of water vapor in the air varies,
from 0% in an arid (dry) environment, to 5%
in tropical rain forests.
Trace elements/compounds
Carbon dioxide: (0.035%) plants use to
produce food. Plants take in CO2 and give
off oxygen as a waste product.
Animals take in oxygen to make energy
and give off CO2 as a waste product.
Ozone Layer
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Ozone Layer
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Trace elements/compounds
(cont’d)
Ozone is a special form of oxygen and is vital
to life on Earth.
Ozone up in the stratosphere blocks out
harmful UV (Ultra-Violet) rays of the sun.
UV rays cause sunburn and can cause
cancer in large amounts.
Use sunscreen!
Ozone near the surface (from pollution) is
poisonous.
Ozone Layer
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Solids and Liquids in the
Atmosphere
There are solids suspended (floating) in the
atmosphere (dust, salt and ice).
There are liquids suspended in the atmosphere
(droplets of clouds).
Water is the only substance that exists as a
solid, a liquid and a gas in the atmosphere.
•Photochemical smog forms when sunlight triggers
reactions and transformations of gases and aerosols.
•Negative effects include burning eyes, sore lungs,
and an unpleasant odor with poor visibility.
•Los Angeles-type smog (above) usually involves dry air while
•London-type smog combines smoke and damp air.
Acid Deposition due to Pollution
Why is the atmosphere important?
Why should I care?
Oxygen and gases for life.
Traps water and energy from the sun.
Protects from harmful rays of the sun.
Keeps most meteoroids from hitting the surface.
Air Around You Review
Simpsons Video Quiz
Tuesday March 23, 2010
• Set Up Your Cornell Notes
• Books Open to page 516.
• Goal/Question: What is air
pressure?
• Notebook Check and Air Around You
were due Friday!
• Progress Reports Today. Due
Thursday 5 points.
Does Air Have Mass?
As you remember, mass is the measure of the
amount of matter or “stuff” in something.
Is air “stuff”?
Since it has mass and takes up space (has
volume), we can also measure its density
What is Air Pressure?
Pressure is the force exerted on an area or
surface (like you).
Atmospheric pressure is the force exerted by air
molecules being pulled toward the surface by
gravity.
– Basically the weight of the air above you.
– about the same as a school bus.
Column of Air
QuickTime™ and a
decompressor
are needed to see this picture.
How does the atmosphere put
pressure onto us?
Atmospheric Pressure and Altitude
Air is most dense at the surface because the air
is pulled down on the lower atmosphere
compressing (squeezing) the air.
Atmospheric (aka Air) pressure is greatest at
sea level. Lowest on tall mountains.
Atmospheric Pressure
At higher altitudes,
the atmosphere
contains fewer
molecules of air.
This means that the
density of air
decreases with
increasing altitude
(as you go up).
Atmospheric Pressure and Altitude
Air is thinner (less
dense) at high
altitudes because
most molecules are
pulled to the
surface.
The earth's atmosphere thins rapidly with increasing altitude and is much
closer to the earth than most people realize.
Measuring Air Pressure
Atmospheric pressure is also called air
pressure or barometric pressure.
– Measured with a Barometer.
Types of Barometers
– Mercury
– Aneroid
– Air pressure is measured in units called
inches of Mercury
Or Millibars
Measuring
Atmospheric Pressure
The mercury BAROMETER
measures the atmospheric
pressure from the balance
between the pressure
exerted by the weight of the
mercury in a tube and the
pressure exerted by the
atmosphere.
As atmospheric pressure
increases and decreases,
the mercury rises and falls.
Mercury Barometer
QuickTime™ and a
decompressor
are needed to see this picture.
Aneroid Barometer
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
Layers of the Atmosphere?
The atmosphere starts
below the surface and
reaches far into space
(120Km/72 miles).
The atmosphere has 4
distinct layers.
What gases are in the
atmosphere?
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Layers of the atmosphere
Earth’s atmosphere has five distinct layers
based on temperature differences.
Let’s draw another one of my famous
pictures.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Vertical Structure - Temperature
4 Thermal Layers
– Troposphere
– Stratosphere
Jet Stream
Ozone Layer
– Mesosphere
– Thermosphere
Ionosphere
exosphere
What layer of the atmosphere
do we live in?
Troposphere
Troposphere — the lowest
thermal layer of the
atmosphere
From Greek tropos (turn)
Lots of vertical mixing and
turbulence
Troposphere
The Troposphere is
warmer near the surface.
Clouds and the surface
absorbs & re-radiates
the sun’s energy
Temperature decreases
(gets colder) with
altitude.
– (altitude = your height
above the ground).
Troposphere
The thickness of the
troposphere varies:
– Because of insolation (the
amount of solar energy
received).
– Latitude
Thicker at equator (11mi/ 18
km)
Thinner at poles (5mi/ 8km)
– Season
Thicker in summer
Thinner in winter
Troposphere
Almost all weather
occurs in the
troposphere.
75% of all the
atmosphere’s
gases are in the
troposphere.
Ft
m
Stratosphere
Stratosphere from Latin
stratum (“a cover”)
– meaning no vertical
mixing.
The jet stream is located
in the stratosphere.
The jet streams are
strong, constant winds
that blow from west to
east.
Stratosphere
Temperature increases
with altitude.
– The higher you go it gets
a little warmer.
– ozone layer absorbs UV
radiation which makes it
warmer.
Stratosphere
The ozone layer is a
layer of gases in the
stratosphere.
It is a special kind of 3atom oxygen.
The ozone layer absorbs
the sun’s harmful UV
rays (Ultraviolet rays).
Stratosphere
In 1961 USAF Cpt. Joseph Kittinger, Jr.,
stepped out of a helium filled balloon 19.5
miles over New Mexico.
As he accelerated to 614 mph in freefall,
his suit fabric didn’t flutter and there was
no sound of rushing wind.
Initially, there was no sense of speed until
he looked up at the balloon getting rapidly
smaller and smaller.
His speed began to decrease as the
atmosphere thickened and wind
resistance slowed his descent
After 4 min., 25 sec., his chute opened at
18,000 ft (3.4 miles)
13 min., 35 sec., later, after falling through
99% of Earth’s atmosphere, he set the
record that still stands today.
Mesosphere
Mesosphere from
Greek meso (“middle”)
Temperature
decreases with altitude
- no heat source
This is the layer in
which meteors burn up
Thermosphere
Thermosphere from Greek
therm (“heat”).
Temperature increases with
altitude due to UV absorption by
molecules in the ionosphere.
Did you know…Heat is the flow
of energy from one body to
another due to a difference
between them
The Ionosphere
Within the thermosphere is
a layer of electrically
charged particles (Ions)
called the ionosphere.
At night, long wavelength
(AM) radio signals bounce
off the ionosphere, allowing
radio signals to travel very
long distances.
Thermosphere/Exosphere
The outer edge of te
thermosphere is called the
exosphere, which blends
into outer space.
Increased solar activity
(sunspots, coronal flares)
can cause thermosphere to
expand and exert drag on
satellites in low orbit.